Amusement parks and theme parks presently operate a variety of rides for the pleasure of their patrons. One type of ride permits vehicles to follow a predetermined path, but with a limited amount of passenger steering. The vehicle is restricted from steering off of the path by a steel rail acting as a physical barrier defining the center of the pathway. During the progression of the ride, if a passenger attempts to steer more than a specified distance from the center of the pathway, the guide wheels on the front wheel steering knuckles of the vehicle collide with the steel rail, causing the vehicle to steer back towards the center of the pathway.
Typically, when the guide wheels of the vehicle collide with the steel rail, an abrupt, uncomfortable impact is felt within the vehicle. To prevent injury to the passenger, the mechanical coupling between the steering wheel and the wheels must be compliant, which causes the steering for the passenger to be imprecise. The impact of the guide wheels colliding with the steel rail also causes increase wear to the vehicle, requiring frequent servicing of the vehicle. Additionally, the visual impression of the center rail taints the experience for the passenger, since it is immediately apparent that the vehicle is constrained to a track.
Similarly, boat rides restrict a passenger's steering by the use of a steel rail or other type of physical barrier. Although the barrier in boat rides can be hidden beneath the water's surface, the barrier still causes an impact with the boat when the passenger steers past a predetermined lateral position or envelope. As mentioned above, such an impact is a disadvantage for an amusement ride. Accordingly, it is important to allow a passenger in an amusement ride to steer a vehicle along a pathway without having a physical barrier or rail constraining the lateral movement of the vehicle, while at the same time restricting the vehicle's lateral movement to a predetermined envelope.
Techniques have been developed for steering vehicles along a predetermined pathway. These techniques have included automatic steering control systems to maintain the vehicle on a specific pathway, as defined by a current-carrying wire embedded beneath the pathway. Typically, in these systems the vehicle is under complete automatic control, without any passenger control. If a lateral displacement of the vehicle is sensed, a signal is directed to the steering mechanism for directing the vehicle along the pathway. Although the vehicle follows the pathway, the passenger is unable to control the vehicle, because the steering of the vehicle is completely automatic.
Alternative techniques have been developed for steering vehicles along a pathway while allowing for automatic or manual control of the vehicle. Typically, in these systems, the vehicle is operable in either of two modes, manual or automatic. Such systems, for example, are used in commercial factory operations. In the manual mode, the vehicle is under the control of a user. On the other hand, in the automatic mode, there is no user interaction for steering the vehicle. While these systems have provided for greater versatility over the completely automatic steering systems, the systems do not allow for responsive passenger steering within a preset lateral distance, while restricting lateral movement of the vehicle to an envelope.
One system previously developed combined both automatic and manual modes. This system was used to guide a vehicle along a pathway defined by a wire. The automatic system provided a force on the steering mechanism that was less than the force the driver of the vehicle could apply if the driver wanted to steer the vehicle manually. While this system helped to guide the vehicle, the driver could manually override the automatic steering system and the vehicle would not be restrained to a preset pathway.
In view of the above, it should be appreciated that there is a need for an apparatus and method for permitting a passenger to steer a vehicle along a pathway, within a predetermined envelope from the center of the pathway, without having a physical barrier to constrain the lateral movement of the vehicle and without allowing the passenger to manually override the vehicle system for detouring from the defined envelope. Such a vehicle system would significantly add to the passenger's experience in an amusement ride, because the system would provide for a vehicle that is responsive to the passenger, while at the same time restricting the vehicle to a predetermined pathway. Thus, the passenger has the visual impression of driving the vehicle on an open road (or boat on water) and the problems associated with vehicle damage, passenger discomfort and imprecise steering, resulting from vehicle collisions with a physical barrier, are vastly reduced. The present invention satisfies these needs.